M45 supercharger pressure and bpv function
01-11-2012, 01:52 PM
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w203 c200K 2.0 mod 02
M45 supercharger pressure and bpv function
I did some datalogging concerning my supercharger pressure today and I have some questions raised:
load 100% rpm 4000 pressure 0,52
load 100% rpm 4500 pressure 0,55
load 100% rpm 5200 pressure 0,51
load 100% rpm 5500 pressure 0,51
load 100% rpm 5800 pressure 0,56
load 100% rpm 6000 pressure 0,60
load 100% rpm 6250 pressure 0,68
my engine is m111 2.0 liter 163 ps with m45 supercharger originally working at 0,37
With my 23cm pulley kit the pressure is almost 0,72 with some pressure drop because of my Fmic.
My questions is:
Given that a roots supercharger gives constant pressure regardless the rpm we know that small pressure drops are due to turbulence reasons and flow improvements on the higher rpm range.
However I could accept this for the drop betwenn 5200-5600. But the differnece of 0,13 bar (4500 rpm -6250rpm) cannot be explained as flow improvement in my book. Is the bpv function rpm related also? (Till now I thought it was related only to the load and intake temp values)
load 100% rpm 4000 pressure 0,52
load 100% rpm 4500 pressure 0,55
load 100% rpm 5200 pressure 0,51
load 100% rpm 5500 pressure 0,51
load 100% rpm 5800 pressure 0,56
load 100% rpm 6000 pressure 0,60
load 100% rpm 6250 pressure 0,68
my engine is m111 2.0 liter 163 ps with m45 supercharger originally working at 0,37
With my 23cm pulley kit the pressure is almost 0,72 with some pressure drop because of my Fmic.
My questions is:
Given that a roots supercharger gives constant pressure regardless the rpm we know that small pressure drops are due to turbulence reasons and flow improvements on the higher rpm range.
However I could accept this for the drop betwenn 5200-5600. But the differnece of 0,13 bar (4500 rpm -6250rpm) cannot be explained as flow improvement in my book. Is the bpv function rpm related also? (Till now I thought it was related only to the load and intake temp values)
